In Arizona, his declaration could become a rallying cry for both sides.

“I think the president took a step toward justice and it’s a consistent step that says all Americans should be treated equally under the eyes of the government,” Lawrence Robinson from Equality Arizona said.

When Obama made the announcement on national television, Robinson said it was a moment of celebration for most of his friends and colleagues, as well as for himself.

“My phone started blowing up with text messages and calls,” he said. “Everyone is relieved to see the president sticking to his guns.”

For the president, this is a politically loaded issue.

But increasing pressure to pick a side led to Wednesday’s announcement.

“For me, personally, I think same sex couples should be able to get married," Obama said, explaining that he believes it's important to "treat others the way you would want to be treated."

Republican presidential candidate Mitt Romney immediately responded, saying while he supports basic rights for gay couples, he does not support gay marriage.

“My view is that domestic-partnership benefits, hospital visitation and the like are appropriate, but the others are not,” Romney said.

Valley attorney Jim Campbell from the Alliance Defense Fund told 3TV he thinks this will shape up to be a big issue leading up to the election.

“The American people are concerned about the issue of marriage,” Campbell said. “They want it to remain the union of a man and a woman.”

The Alliance Defense Fund fights against gay marriage nationwide.

We asked if Obama’s announcement in support of gay couples will make that fight more difficult.

“This is one politician's view about what he seemingly wants to redefine as marriage. But Americans across the country want to protect the union between man and woman.”